The present invention relates, generally, to an apparatus for removing components having an adhesive backing from a carrier tape and applying those components directly onto a substrate or item, and a method for doing the same. More particularly, the present invention is directed to an automated method and apparatus for removing and applying adhesive backed components to a substrate or other item utilizing a retracting blade assembly wherein the movement of the retracting blade assembly does not move the carrier or change the position of any components contained on the carrier.
There are a number of label applicators known in the prior art. Labels are frequently packaged on a carrier liner or web tape and rolled up to hold a large volume of labels. A typical automated application system allows the user to load a roll of labels and string the carrier liner or web tape through various rollers and drives that provide tension and automatic feed capability. Although many of these label applicators are described with specific reference to the application of labels, many of the same components and concepts used in these applicator systems may apply to the application of other items in addition to labels.
For example, U.S. Pat. No. 4,132,583, issued to Hodgson, discloses an automatic applicator that applies strip-mounted labels to both flat and curved objects. A pressure foot applies a label already positioned on the foot to an object that is brought into position by pressing the entire surface of the label against the object. The label strip is advanced over a stripper plate by a preset amount that is determined by a label edge sensor as each object moves out of position. Meanwhile, the pressure foot simultaneously swings toward the stripper plate and picks up the next label being peeled from the strip.
In another example, U.S. Pat. No. 4,255,220, issued to Kucheck et al., describes a label applicator having a supporting structure and a label receiver mounted on the supporting structure for movement between a retracted position and an extended position. A label dispenser supplies a label to the label receiver when the label receiver is in the retracted position and the label is transferred by an air blast from the label receiver to an article when the label receiver is moved to the extended position. In still another example, U.S. Pat. No. 5,849,143, issued to Ingalls, describes a precision label application system for applying adhesive labels from a feed web onto flat uniform size articles. The advance of the article to be labeled and the advance of the current label to be applied are mechanically linked to occur in unison so that forward advancement speed of the article and the current label are matched exactly.
In yet another example, U.S. Pat. No. 5,835,530, issued to Allen discloses a label applicator having a supporting structure, a label receiver having a receiving face and being adapted to receive and releasably retain a label, and a label dispenser adapted to dispense a label onto the receiving face. The dispenser is further adapted to blow gas against the trailing and lower edges of the label as it is transferred from the label dispenser onto the receiving face to assist moving the label onto the receiving face. The receiving face is fitted with a stop plate and, after positioning the label on the receiving face, the label is applied to the article.
Still other patents describe methods and apparatus for peeling and applying adhesive components, including labels, double sided adhesive strips, gaskets, and thermal transfer tapes, onto other items. In U.S. Pat. No. 5,938,890, issued to Schlinkmann et al., a system for peeling and applying an adhesive component is described which is based on one or more sensors that locate the component and feed the component on its web tape on the surface of a retracting blade to a specified position underneath a vacuum chuck. The vacuum chuck then presses against the component, its web tape, and the retracting blade underneath the web tape, while a clamp simultaneously clamps the web tape to arrest its motion. The clamp is positioned before the retracting blade so that a drive roller system can only take up the web tape between itself and the clamp when it is engaged. When the component is securely held by the vacuum, the drive roller system begins pulling the web tape thereby causing the retracting blade to retract and peel the web tape from underneath the component. The vacuum chuck then places the component onto an item and returns to its home position. The drive roller system feeds the carrier in the reverse direction, creating slack, and allowing a spring device attached to the blade to return the blade to its extended position.
A key factor in the process described above with reference to Schlinkmann is the use of a retracting blade. The retracting blade is a moving plate that the web tape travels over. When the retracting blade is fully extended, the web tape can be fed over it and the blade serves as a surface to push against when gaining hold of the component. In this type of apparatus, the blade is usually attached to a spring device that applies pressure to keep the blade at the extended position. When the web tape is clamped at a position before the retracting blade, the drive assembly pulls on the web tape and the tension on the web tape overcomes the force of the retracting blade spring causing the retracting blade to retract. As long as the vacuum pressure is sufficient, the adhesive component will remain in position on the vacuum chuck and will be released from the web tape.
Although the presently known methods and apparatus for peeling and applying adhesive backed components are automated for efficiency, there is a need for a method and apparatus for applying components that requires fewer motions and exhibits faster speeds in order to significantly reduce the overall cycle time. There is also a need for a method and apparatus where a web tape or carrier for carrying components is not subject to high tensions which sometimes result in breaks and tears in the web tape or carrier thereby causing system downtime.
Briefly, the present invention is directed to a method and apparatus for removing and applying adhesive backed components to a substrate where advancement of a carrier, which contains the adhesive backed components, and movement of a retracting blade occur simultaneously to improve or decrease cycle time. The method and apparatus also include the use of a tensioner which functions to maintain the tension of the carrier in order to avoid limiting acceleration of blade extension and retraction speeds as well as breaks and tears in the carrier.
In accordance with one embodiment of the present invention, an apparatus for removing an adhesive backed component from a carrier and applying the component onto a substrate includes a first means for capturing the carrier, a second means for capturing the carrier, a retracting blade assembly located between the first and second capturing means having a top surface of a retracting blade for retaining a portion of the carrier, a first roller affixed to, and moving with, the retracting blade which rotates while the retracting blade is in motion, and a second roller permanently affixed in place between the first roller and the second capturing means which rotates when the carrier is moved through the apparatus.
In accordance with one aspect of the invention, the first capturing means comprises a web clamp or a brake and the second capturing means comprises a feed drive roller and pinch drive roller combination or similarly functioning element or elements including, but not limited to, a take up feature with an encoder, a linear actuator with a clamp, or a tractor feed used in combination with holes formed through the carrier.
In accordance with another aspect of the present invention, the apparatus for removing an adhesive backed component from a carrier and applying it to a substrate may also include a tension element which applies tension to the carrier in order to maintain a predetermined tension of the carrier.
In accordance with yet another aspect of the present invention, the retracting blade assembly further includes an element or elements that produce a controlled linear motion for moving the top surface of the retracting blade. The element or elements may include, but are not limited to, a rack and pinion with a gear motor, a linear motor, a voice coil actuator, a motor belt configuration, or any other means known in the art for producing a controlled linear motion.
In accordance with still another aspect of the present invention, the retracting blade is capable of extending to a predetermined position while the feed drive roller advances the carrier to a predetermined location so that the retracting blade and the carrier move simultaneously and independently from one another. Further, movement of the retracting blade assembly does not result in movement of the carrier located on the top surface of the retracting blade.
In accordance with yet another aspect of the present invention, the apparatus may include one or more sensors positioned over the retracting blade which assist in sensing a feature of the component or portion of the carrier and inputting information related to its location so that the retracting blade and carrier can be extended and advanced to their predetermined position and location, respectively. The predetermined position and location for the retracting blade and carrier may be preprogrammed using computer software. Also, the linear acceleration and velocity of the carrier controlled by the second capturing means may be synchronized with the linear acceleration and velocity of the retracting blade by electrical or mechanical means.
In another embodiment of the present invention, a method for removing an adhesive backed component from a carrier and applying the component onto a substrate is presented which includes the steps of positioning a carrier tape having adhesive backed components over a top surface of a retracting blade, simultaneously extending the retracting blade and the carrier tape to a predetermined position; applying a vacuum chuck to a component on the carrier located at the predetermined position, removing the component from the carrier with the vacuum chuck by retracting the retracting blade, applying the component to a substrate utilizing the vacuum chuck, and retracting the vacuum chuck to its original starting position.
Advantages of the present invention include a significant reduction in cycle times as a result of advancing the carrier while simultaneously extending the retracting blade, and elimination of the need for the carrier to travel around the edge of the retracting blade as it advances thereby reducing rippling in the carrier that can cause misreading of the carrier position by the sensor(s). Furthermore, retracting blade extension and retraction velocities are not limited by the properties of the carrier.